The overall objectives of this study are to investigate the feasibility of using D-glucosamine and other amino sugars as potentiatng agents for cancer chemotherapy, and to define more clearly the basis for cytotoxicity of amino sugars in tumor cells. D-glucosamine (and other amino sugars) are capable of lowering cellular pyrimidine nucleotide pools, and inhibiting the salvage pathway for thymidine utilization. Current research involves screening for drugs which synergize with D-glucosamine in killing glial tumor cells in vitro. The mechanisms of action and structure-activity relationships of several such drug combinations are presently being studied. BIBLIOGRAPHIC REFERENCES: S. Friedman, Trotter, C.D., Kimball, T. and Skehan, P. The inhibition of thymidine metabolism in tumor cells treated with D-glucosamine. Cancer Research, April 1977, in press. Friedman, S., Kimball, T., Trotter, C.D. and Skehan, P. The inhibition of thymidine kinase in glial tumor cells by an amino sugar, D-glucosamine. Cancer Research, April, 1977, in press.